EP0129734A2 - Herstellung und Anwendung von Elektroden - Google Patents

Herstellung und Anwendung von Elektroden Download PDF

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Publication number
EP0129734A2
EP0129734A2 EP84106102A EP84106102A EP0129734A2 EP 0129734 A2 EP0129734 A2 EP 0129734A2 EP 84106102 A EP84106102 A EP 84106102A EP 84106102 A EP84106102 A EP 84106102A EP 0129734 A2 EP0129734 A2 EP 0129734A2
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Prior art keywords
metal
metal oxide
substrate
coating
cathode
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EP84106102A
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English (en)
French (fr)
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EP0129734A3 (en
EP0129734B1 (de
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R. Neal Beaver
Lloyd E. Alexander
Carl E. Byrd
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Dow Chemical Co
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Dow Chemical Co
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/052—Electrodes comprising one or more electrocatalytic coatings on a substrate
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/091—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/091—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
    • C25B11/093—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds at least one noble metal or noble metal oxide and at least one non-noble metal oxide

Definitions

  • This invention pertains to a method for preparing electrodes and to their use in electrolytic cells, for example, brine electrolysis cells.
  • electrolytic cells used for the production of chlor-alkali: (1) the mercury cell, (2) the diaphragm cell, and (3) the membrane cell. The operation of each of these cells is discussed in Volume 1 of the Third Edition of the KIRK-OTHMER ENCYCLOPEDIA OF CHEMICAL TECHNOLOGY, page 799 et. seq.
  • Other electrolytic cells which employ electrodes for electrolysis of aqueous solutions are the so-called "chlorate cells" which do not use a divider or separator between the cathodes and anodes.
  • the alkali metal values produced by electrolyzing an alkali metal salt form an amalgam with the mercury; the amalgam, when reacted with water, produces NaOH and frees the mercury which can be recovered and cycled back for further use as a liquid cathode.
  • a brine solution (electrolyte) is electrolyzed by passing electric current therethrough in a cell having a diaphragm or a membrane positioned between the cathode and the anode.
  • Chlorine is produced at the anode while sodium hydroxide (NaOH) and hydrogen (H 2 ) are formed at the cathode.
  • Brine is fed continuously to the cells, while C1 2 , NaOH and H 2 are continuously withdrawn from the cells.
  • the minimum voltage required to electrolyze an electrolyte into C1 2 , NaOH and H 2 may be calculated using the thermodynamic data. However, in commercial practice, the theoretical amount of voltage is not achievable and higher voltages must be used to overcome the various resistances inherent in the various types of cells. To increase the efficiency of the operation of a diaphragm or a membrane cell one may attempt to reduce the overvoltages of the electrodes, to reduce the electrical resistance of the diaphragm or membrane, or reduce the electrical resistance of the brine being electrolyzed.
  • the invention herein described results in an electrode particularly useful as a cathode in the electrolysis of brine; cathode overvoltage is substantially reduced, resulting in increased power efficiencies.
  • the present disclosure pertains, in part, to a novel process to make an electrode that is characterized by a significantly low overvoltage and to the use of these electrodes in electrolytic cells.
  • an electrode's overvoltage is a function of the current density and its composition (reference: PHYSICAL CHEMISTRY, 3rd ed., W. J. Moore, Prentice Hall (1962), pp. 406-408), where the current density refers to the amperage applied per unit of true surface area of an electrode and composition refers to the chemical and physical makeup of the electrode. Therefore, a process that will increase an electrode's surface area should decrease its overvoltage at a given apparent current density. It is also desirable to use a composition of matter that is a good electrocatalyst; this further reduces the overvoltage.
  • Cathodes also, have been coated with electroconductive metals.
  • cathodes were coated by plasma spraying or flame spraying an admixture of particulate cobalt and particulate zirconia.
  • these electrodes are used for the electrolysis of water or an aqueous alkali metal halide salt solution, they are said to give prolonged lowering of hydrogen overvoltage.
  • U.S. Patent No. 3,630,770 teaches the use of lanthanum boride
  • U.S. Patent No. 3,649,355 teaches the use of tungsten or tungsten alloy
  • U.S. Patent No. 3,788,968 teaches the use of titanium carbide or titanium nitride and at least one metal and/or metal oxide of the platinum group and a second oxide coating which is porous
  • U.S. Patent No. 3,945,907 teaches the use of rhenium
  • U.S. Patent No. 3,974,058 teaches the use of cobalt as a coating with an overcoat of ruthenium.
  • U.S. Patent No. 3,497,425 teaches preparing porous electrodes by coating the substrate with a relatively insoluble metal followed by a coating of a more easily dissolvable metal.
  • the teaching requires heat treating to cause inter-diffusion of the two coats, while optimum conditions require separate heat treatments for each coat. The dissolvable metal is subsequently leached out, leaving a porous electrode.
  • U.S. Patent No. 3,618,136 teaches forming porous electrodes by coating a binary salt composition onto a substrate and leaching a soluble component from the system. The patent teaches that it is critical that the binary salt mixture is a eutectic composition and that optimum results are obtained when the same anions are used for both the active and the inactive salts, e.g. silver chloride -- sodium chloride.
  • Netherlands Patent Application No. 75-07550 teaches the preparation of porous cathodes by applying to a substrate a coating of at least one non-noble metal from the group of nickel, cobalt, chromium, manganese and iron, alloyed with a secondary, less noble, sacrificial metal followed by removal of at least a part of this sacrificial metal.
  • the sacrificial metal is chosen from the group of zinc, aluminum, magnesium and tin. The sacrificial metal is removed by leaching with a lye solution or an acid solution.
  • Japanese Patent No. 31-6611 teaches forming a porous electrode by electroplating onto a substrate a nickel coating followed by a coating of zinc or some other soluble substance which is soluble in an alkaline solution. These coated electrodes are then either immersed in an alkaline solution or subjected to an electrochemical anodizing treatment to elute and remove zinc and other soluble substances, thus forming a porous electrode. Prior to immersion, a heat treatment of the coated electrode is required in some embodiments.
  • U.S. Patent No. 4,279,709 discloses a method for making electrodes including electrodes having reduced overvoltage by applying an admixture of particulate metal and a particulate inorganic compound pore-former and then leaching out the pore-former to form pores.
  • Electrodes of film-forming metal substrates, especially titanium, coated with oxides of Group VIII metals of the Periodic Table of The Elements have been taught, especially conjointly with other metal oxides, as being useful as anodes in electrolytic processes, such as in brine electrolysis.
  • Ruthenium oxides, platinum oxides, and other oxides of the "platinum metal series” in association with various other metal oxides have received much acclaim as coatings for valve metal substrates (esp. Ti) for use as anodes.
  • Patents relating to such anodes are, e.g. U.S. Patent Nos. 3,632,498 and 3,711,385. These coatings may be applied in several ways, for example, U.S. Patent No.
  • 3,869,312 teaches that platinum group metal oxides, combined with film-forming metal oxides may be deposited on valve metal substrates by applying a mixture of thermally--decomposable compounds of platinum group metals and a thermally-decomposable organo-compound of a film-forming metal in an organic liquid vehicle which may also optionally contain a reducing agent, to a support member, drying the coating by evaporation of the organic vehicle, then heating the member in the range of 400-550°C to form metal oxides. Repeated coats are applied to increase the thickness of the coating. Also an overcoating of a film-forming metal oxide is applied.
  • Patent 3,632,498 teaches that coatings of finely divided oxides of platinum group metals and film-forming metals may be produced by use of a plasma burner, by heating substrates which have been coated with thermally--decomposable compounds of platinum group metals and film-forming metals, by electrically depositing the metals in a galvanic bath followed by heating in air to form the oxide, among others.
  • Oxide coatings prepared according to the known art are found to decrepitate with use and fail by loss of adherence to the substrate, accompanied presumably by substantial reduction, in some cases, to base metals.
  • catalytic coatings consisting of metals with intrinsically low hydrogen overvoltage properties are subject in actual practice to loss of catalytic activity due to overplating with metallic contaminants, such as iron for example, which are commonly present in brine and water employed in the process of electrolysis. Consequently, active coatings found useful by those practiced in the art for evolution of hydrogen in modern electrolytic membrane chlor-alkali cells are limited to the type characterized by high surface area, or porous coatings, with compositions resistant to some degree to chemical attack at these conditions, e.g. nickel or various stainless steels.
  • the invention particularly resides in a method of making a low hydrogen overvoltage cathode which comprises applying to an electroconductive substrate a coating solution of metal oxide precursor compound(s) and an etchant capable of etching the surface of the substrate and/or any previously applied coating, heating to remove volatiles from the so-coated substrate to cause the metal values of the precursor compounds and those etched from the substrate or previous coating to be concentrated and recoated on the substrate or previously applied coating, and further heating, in the presence of oxygen, air or an oxidizing agent, to a temperature sufficient to oxidize the metal values.
  • FIG 1 illustrate graphically data from some of the tests described hereinafter.
  • Electrodes comprising an electrically conductive, or non-conductive substrate having a coating of heterogeneous oxide mixtures of platinum group metals and secondary electrocatalytic metals are prepared by applying soluble metal compounds and an etchant for the substrate, and, in cases of successive coats, etching the metal oxides previously applied to the substrate, thereby, it is believed, attacking and solubilizing the least chemically resistant portions of the coating, then, as the substrate is heated to oxidize the metal values, concentrating and redepositing the said metal values on the substrate, and oxidizing them to produce a substantially hard, stable mixture of heterogeneous oxides of the metal values.
  • the preferred electrically-conductive substrate may be any metal structure which retains its physical integrity during the preparation of the electrode.
  • Metal laminates may be used, such as a ferrous metal coated with another metal, e.g., nickel or a film-forming metal (also known as valve metal).
  • the substrate may be a ferrous metal, such as iron, steel, stainless steel or other metal alloys wherein the major component is iron.
  • the substrate may also be a non-ferrous metal, such as a film-forming metal or a non-film-forming metal, e.g., Ni.
  • Film-forming metals are well known in these relevant arts as including, notably, titanium, tantalum, zirconium, niobium, tungsten and alloys of these with each other and with minor amounts of other metals.
  • Non-conductive substrates may be employed, especially if they are then coated with a conductive layer onto which the instant metal oxides are deposited.
  • the shape or configuration of the substrate used in the present coating process may be a flat sheet, curved surface, convoluted surface, punched plate, woven wire, expanded metal sheet, rod, tube, porous, non-porous, sintered, filamentary, regular, or irregular.
  • the present novel coating process is not dependent on having a substrate of a particular shape, since the chemical and thermal steps involved are applicable to virtually any shape which could be useful as an electrode article.
  • Many electrolytic cells contain foraminous (mesh) sheets or flat plate sheets; these are sometimes bent to form "pocket" electrodes with substantially parallel sides in a spaced-apart relationship.
  • the preferred substrate configuration comprises expanded mesh, punched plate, woven wire, sintered metal, plate, or sheet, with expanded mesh being one of the most preferred of the porous substrates.
  • the preferred composition of the substrate comprises nickel, iron, copper, steel, stainless steel, or ferrous metal laminated with nickel, with nickel being especially preferred. It will be understood that these substrates, onto which the metal oxide coatings are to be deposited, may themselves be supported or reinforced by an underlying substrate or member, especially where nickel, iron, or copper is carried by, or on, an underlying substrate or member.
  • the substrate, onto which the metal oxide coating is to be deposited may itself be an outer layer of a laminate or coated structure, and it may be, optionally, a non-conductive substrate onto which the metal oxide coating is deposited.
  • the platinum metal series comprises Ru, Rh, Pd, Os, Ir, and Pt. Of these, the preferred metals are platinum and ruthenium, with ruthenium being most preferred.
  • the soluble platinum metal compound may be the halide, sulphate, nitrate or other soluble salt or soluble compound of the metal and is preferably the halide salt, such as RuCl 3 -hydrate, PtC1 4 .hydrate, and the like.
  • the secondary electrocatalytic metal oxide precursor of the present coating may be at least one derived from a soluble compound of Ni, Co, Fe, Cu, W, V, Mn, Mo, Nb, Ta, Ti, Zr, Cd, Cr, B, Sn, La, or Si.
  • a soluble compound of Ni, Co, Fe, Cu, W, V, Mn, Mo, Nb, Ta, Ti, Zr, Cd, Cr, B, Sn, La, or Si The preferred of these are Ni, Zr, and Ti, with Ni being the most preferred.
  • the solution of the present invention contains at least one chemically active agent capable of etching the substrate, and, in the case of second and later coatings, etching and solubilizing the most chemically--susceptible portions of the oxides.previously formed, while also, preferably as the temperature is elevated, vaporizing, in many cases, from the heated mixture, along with volatilized anions or negative-valence radicals from the platinum metal oxide precursor and the secondary electrocatalytic metal oxide precursor.
  • the preferred chemically active etchants comprise most common acids, such as hydrochloric acid, sulphuric acid, nitric acid, phosphoric acid; also hydrazine hydrosulphate, and the like, with hydrochloric acid and hydrazine hydrosulphate being among the most preferred.
  • the preferred method contemplated in the present invention comprises applying to the desired substrate a solution containing at least one platinum metal series compound, at least one electrocatalytic metal compound, and a chemical etchant, preferably containing a volatile organic vehicle, such as isopropanol, and allowing the volatile vehicle to evaporate, leaving the etchant and the dissolved metal values; then heating the substrate to-a temperature sufficient to concentrate the metal values, also substantially driving out the volatilized etchant along with the anions or negative-valence radicals released from the metal oxide precursors, and heating the substrate in the presence of oxygen or air to a temperature sufficient to thermally oxidize and convert the metals to metal oxides in-situ on the substrate.
  • a solution containing at least one platinum metal series compound, at least one electrocatalytic metal compound, and a chemical etchant preferably containing a volatile organic vehicle, such as isopropanol
  • the steps may be repeated a plurality of times in order to attain the best full effect of the invention by increasing the thickness of the coating. Furthermore there is, at times, a benefit to be derived from laying down 2 or more layers of the metal oxide precursors between each thermal oxidation step.
  • an electrode material is prepared by applying a heterogeneous metal oxide coating, said heterogeneous metal oxide coating comprising nickel oxide and a platinum group metal oxide (optionally containing a modifier metal oxide, e.g., ZrO .
  • a nickel metal layer (which may be in the form of a nickel layer on an electroconductive substrate) by the process which comprises (a) applying to said nickel metal layer a coating solution comprising a nickel oxide precursor, a platinum group metal oxide precursor, an optional modifier metal oxide precursor, and an etchant for dissolving the most soluble portions of the nickel metal surface, (b) heating to evaporate volatile portions of the coating solution, thereby concentrating and depositing the metal oxide precursors on the so-etched nickel metal surface, (c) heating in the presence of air or oxygen at a temperature between 300°C to 600°C for a time sufficient to oxidize the metals of the metal oxide precursors, and (d) cooling the so-prepared electrode material.
  • Additional coatings may be applied in similar manner so as to increase the thickness of the so-produced heterogeneous metal oxide coating on the nickel metal surface, though the etchant for the second and later coating applications may beneficially be the same as, or different from, the etchant used in the initial coating application.
  • an electrode material comprising a nickel metal layer having tightly adhered thereto a heterogeneous metal oxide coating comprising nickel oxide and a platinum group metal oxide, optionally also containing a modifier metal oxide.
  • the platinum group metal oxide is ruthenium oxide.
  • the preferred optional modifier metal oxide is zirconium oxide.
  • An economical form of the nickel metal layer is that of a nickel layer on a less expensive electroconductive substrate, such as steel or iron alloys. Such electrode material is particularly useful as cathodes in chlor-alkali cells.
  • the temperatures at which thermal oxidation of the metals is achieved is somewhat dependent on the metals, but a temperature in the range of from 300° to 650°C, more or less, is generally effective. It is generally preferred that the thermal oxidation be performed at a temperature in the range of from 350° to 550°C.
  • the effect of the invention is to produce a substantially hard, adherent coating of heterogeneous oxides of the solubilized metals.
  • solubilization, reconcen-. tration, and in-situ deposition of the solubilized metals, using chemical etching of the previously deposited layers and/or substrate produces an intimate mixture of oxides which are mutually stabilizing and electrocatalytically complementary.
  • a solution was prepared which consisted of 1 part RuCl 3 ⁇ 3H 2 O, 1 part NiCl 2 ⁇ 6H 2 O, 3.3 parts H 2 NH 2 ⁇ H 2 SO 4 (hydrazine hydrosulphate), 5 parts H z O, and 28 parts isopropanol.
  • the solution was prepared by first mixing together all ingredients other than the isopropanol by stirring overnight, then adding the isopropanol and continuing to stir for approximately 6 hours.
  • a cathode was prepared which was constructed of a 40% expanded mesh of nickel.
  • the cathode was first sandblasted, then etched in 1:1 HCl. It was subsequently rinsed, dipped in isopropanol and air dried.
  • the cathode was coated by dipping it into the coating solution, allowing it to air dry, then baking it in an oven at 375°C for 20 minutes. In the same manner, a total of 6 coats were applied.
  • the cathode was immersed in a heated bath containing 35% NaOH at a temperature of 90°C. A current was applied and potential measurements were taken using a standard Calomel Reference Electrode (SCE) and a Luggin probe.
  • SCE Calomel Reference Electrode
  • the cathode potential was measured at -1145 millivolts vs. SCE at a current density of 2 amps per square inch (0.31 amps per cm 2 ).
  • the cathode was assembled in a laboratory membrane chlorine cell and operated at 90°C, producing Cl 2 at the anode and H 2 at the cathode, at 31-33% NaOH concentration, operating at 0.31 amp/cm 2 (2 amp/in 2 ) current density.
  • the potential of the cathode was monitored and averaged per week. The results are shown in Table I.
  • a solution was prepared which consisted of 1 part RuCl 3 ⁇ 3H 2 O, 1 part NiCl 2 ⁇ 6H 2 O, and 3.3 parts concentrated HC1. It was allowed to mix overnight. Subsequently, 33 parts isopropanol were added and mixing continued 2 hours.
  • a cathode was prepared in accordance with the procedure of Example 1. The cathode was then coated in the same manner as Example 1 except baking was carried out at a temperature of 495°-500°C. Ten coats were applied. The cathode potential was measured as in Example 1. The potential was -1135 millivolts vs. SCE. The cathode was assembled in a laboratory cell containing a commercially available NAFION * polymer ( * a tradename of E. I.
  • a solution was prepared which consisted of 1 part NH 2 0H.HCl, 5 parts concentrated HC1, 2 parts 10% H 2 PtCl 6 ⁇ 6H 2 O, 1 part NiCl 2 ⁇ 6H 2 O, and 1 part RuCl 3 ⁇ 3H 2 O. The solution was allowed to mix for 12 hours. Then 75 parts isopropanol were added and mixing continued for 2 hours.
  • a cathode was prepared according to Example 1. The cathode was then coated in the same manner as Example 1. except baking was carried out at a temperature of 470°-480°C. Five coats were applied. A sixth coat was applied and the electrode was baked for 30 minutes at a temperature of 470°-480°C. The potential of the cathode was measured as in Example 1.
  • the potential was -1108 millivolts vs. SCE.
  • the cathode was assembled in a laboratory membrane chlorine cell containing a commercialy available membrane, as in Example 2. The cell was operated at 90°C, 31-33% NaOH, and 0.31 amp/cm 2 (2 amp/in 2 ) current density. The potential of the cathode was monitored and averaged per week. The results are shown in Table I.
  • a solution was prepared which consisted of 3 parts RuCl 3 ⁇ 3H 2 O, 3 parts NiCl 2 ⁇ 6H 2 O, 1 part ErCl 4 , 5 parts concentrated HC1, and 42 parts isopropanol. The solution was allowed to mix 2 hours.
  • the cathode was then coated in the same manner as Example 1 except baking was carried out at a temperature of 495°-500°C. Eight coats were applied. A ninth coat was applied and the electrode was baked for 30 minutes at a temperature of 470°-480°C.
  • the potential of the cathode was measured as in Example 1. The potential was -1146 millivolts vs. SCE.
  • the cathode was assembled in a laboratory membrane chlorine cell containing a commercially available membrane, as in Example 2. The cell was operated at 90°C, 31-33% NaOH, and 0.31 amp/cm 2 (2 amp/in 2 ) current density. The potential of the cathode was monitored and averaged per week. The results are shown in Table I.
  • a cathode was prepared as in the previous examples, then dipped in a solution containing 1 gram of tetraisopropyl titanate in 100 ml of isopropanol. The cathode was then baked at a temperature of 475°-500°C for 10 minutes. Three coats were applied. A solution was prepared as in Example 2. The cathode was dipped in the solution, air dried, and baked at a temperature of 475°-500°C. Six coats were applied. The potential of the cathode was measured as in the previous examples. The potential was -1154 millivolts vs. SCE. The cathode was assembled in a laboratory membrane chlorine cell containing a commercially available membrane, as in Example 2. The cell was operated at 90°C, 31-33% NaOH, and 0.31 amp/cm 2 (2 amp/in 2 ) current density. The potential of the cathode was monitored and averaged per week. The results are shown in Table I and also in Figure 1.
  • a 40% expanded mesh electrode of steel was prepared, but not coated, and assembled as the cathode in a laboratory cell as in Examples 2-5, using the same type membrane. The potential of the cathode was monitored and averaged per week. The results are shown in Table I.
  • a 40% expanded mesh electrode of nickel was prepared, but not coated, and assembled as the cathode in a laboratory cell as in Examples 2-5, using the same type membrane.
  • the potential of the cathode was monitored and averaged per week. The results are shown in Table I and also in Figure 1. to each other, though all are believed to be slightly lower than what one should expect to find from a theoretical calculation.
  • the actual absolute reversible voltage should be about -1.093V for a cell at 90°C, 31-33% NaOH, and at a current density of 0.31 amp/in 2 (2 amp/in 2 ).
  • the cells of Examples 2-7 were operated at 90°C, 31-33% NaOH, and 0.31 amp/cm 2 (2 amp/in 2 ) current density while maintaining atmospheric pressures in the anolyte and catholyte compartments of the cell.
  • Sodium chloride brine and water were fed to the anolyte and catholyte compartments, respectively, in order to maintain anolyte concentrations in the range 180-200 grams per liter NaCl and 31-33% NaOH.
  • Internal mixing of the cells was accomplished by natural gas lift due to evolution of hydrogen gas at the cathode and chlorine gas at the anode. Data including mass and energy balances were collected periodically over the period of operation of the cells and energy requirements for the production of NaOH were calculated. The results are shown in Table 2.
  • the series were operated at pressures of 101,325 to 202,650 Pa (1 to 2 atmospheres) while recirculating the anolyte and the catholyte through the cells using centrifugal pumps.
  • the ratio of the catholyte flow to the anolyte flow was maintained at a value greater than 1.
  • Energy and mass balance data were collected and average performance data were calculated over a period of 45 days. The results clearly show that the energy savings attained with the use of the electrodes of the present invention (Series 1) averaged greater than a 5% reduction in energy, compared with Series 2.
  • the present novel electrodes are especially suitable for operation in the elevated temperature range of from 85° to 105°C. Pressures at around 101,325 Pa (1 atm.), more or less, are ordinarily used in chlor-alkali cells, though pressures up to about 303,975 Pa (3 atm.) or more may be used.
  • the electrodes of the present invention are useful in cells wherein circulation within each electrolyte compartment is created by the gas-lift (displacement) action of gaseous products produced therein, though in some cells, such as in electrolyte series flow from cell-to-cell, another pumping means may be provided to supplement, or substitute for, the gas-lift action.
  • another pumping means may be provided to supplement, or substitute for, the gas-lift action.
  • the electrodes of this invention are useful in chlor-alkali electrolytic cells in which the anolyte has, or is adjusted to have, a pH in the range of from 1 to 5, such as when an acid, e.g. HC1, is added to the anolyte.
EP84106102A 1983-05-31 1984-05-29 Herstellung und Anwendung von Elektroden Expired - Lifetime EP0129734B1 (de)

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AT84106102T ATE50003T1 (de) 1983-05-31 1984-05-29 Herstellung und anwendung von elektroden.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US49962683A 1983-05-31 1983-05-31
US499626 1983-05-31

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EP0129734A2 true EP0129734A2 (de) 1985-01-02
EP0129734A3 EP0129734A3 (en) 1985-06-05
EP0129734B1 EP0129734B1 (de) 1990-01-31

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EP (1) EP0129734B1 (de)
JP (1) JPS59232284A (de)
KR (1) KR870001769B1 (de)
AT (1) ATE50003T1 (de)
AU (1) AU580002B2 (de)
BR (1) BR8402693A (de)
CA (1) CA1246008A (de)
CS (1) CS273157B2 (de)
DD (1) DD253648A1 (de)
DE (1) DE3481203D1 (de)
FI (1) FI75872C (de)
HU (1) HU201124B (de)
IN (1) IN161186B (de)
NO (1) NO164487C (de)
PL (1) PL143728B1 (de)
ZA (1) ZA844069B (de)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3344416A1 (de) * 1983-12-08 1985-12-05 Sigri GmbH, 8901 Meitingen Verfahren zur herstellung einer kathode fuer die waesserige elektrolyse
FR2579628A1 (fr) * 1985-03-29 1986-10-03 Atochem Cathode pour electrolyse et un procede de fabrication de ladite cathode
WO1986006108A1 (en) * 1985-04-12 1986-10-23 Oronzio De Nora Impianti Elettrochimici S.P.A. Electrodes for use in electrochemical processes and method for preparing the same
EP0129088B1 (de) * 1983-06-21 1987-05-20 SIGRI GmbH Kathode für wässrige Elektrolysen
EP0298055A1 (de) * 1987-06-29 1989-01-04 Permelec Electrode Ltd Kathode für Elektrolyse und Verfahren zur Herstellung derselben
US4938851A (en) * 1984-12-14 1990-07-03 De Nora Permelec S.P.A. Method for preparing an electrode and use thereof in electrochemical processes
WO1992022909A1 (en) * 1991-06-13 1992-12-23 Purdue Research Foundation Solid state surface micro-plasma fusion device
WO2023037010A3 (en) * 2021-09-13 2023-05-19 Magneto Special Anodes B.V. An electrolyzer electrocatalyst comprising cobalt (co) oxide, zirconium (zr) and a noble metal, an electrode comprising the electrocatalyst and the use of the electrocatalyst in an electrolysis process

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JP4142191B2 (ja) * 1999-02-24 2008-08-27 ペルメレック電極株式会社 活性化陰極の製造方法
TW200304503A (en) 2002-03-20 2003-10-01 Asahi Chemical Ind Electrode for generation of hydrogen
CN1938453B (zh) 2004-04-23 2010-10-20 东曹株式会社 用于产生氢的电极及其制造方法和使用该电极的电解方法
JP4578348B2 (ja) * 2005-03-24 2010-11-10 旭化成ケミカルズ株式会社 水素発生用電極
JP5317012B2 (ja) * 2009-03-11 2013-10-16 ダイソー株式会社 低水素過電圧陰極の製法
JP5429789B2 (ja) * 2009-04-21 2014-02-26 国立大学法人東北大学 電気透析装置
JP6515509B2 (ja) * 2013-12-26 2019-05-22 東ソー株式会社 水素発生用電極およびその製造方法並びにこれを用いた電気分解方法
JP6609913B2 (ja) * 2013-12-26 2019-11-27 東ソー株式会社 水素発生用電極およびその製造方法並びにこれを用いた電気分解方法

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US3990957A (en) * 1975-11-17 1976-11-09 Ppg Industries, Inc. Method of electrolysis
FR2311108A1 (fr) * 1975-05-12 1976-12-10 Hodogaya Chemical Co Ltd Cathode activee pour electrolyse
US4100049A (en) * 1977-07-11 1978-07-11 Diamond Shamrock Corporation Coated cathode for electrolysis cells
EP0046449A1 (de) * 1980-08-18 1982-02-24 Eltech Systems Corporation Dimensionsstabile beschichtete Elektrode für elektrolytische Verfahren mit einer Oxyde enthaltenden Zwischenschutzschicht auf Ventilmetallbasis und Verfahren zur Herstellung der Elektrode

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FR2311108A1 (fr) * 1975-05-12 1976-12-10 Hodogaya Chemical Co Ltd Cathode activee pour electrolyse
US3990957A (en) * 1975-11-17 1976-11-09 Ppg Industries, Inc. Method of electrolysis
US4100049A (en) * 1977-07-11 1978-07-11 Diamond Shamrock Corporation Coated cathode for electrolysis cells
EP0046449A1 (de) * 1980-08-18 1982-02-24 Eltech Systems Corporation Dimensionsstabile beschichtete Elektrode für elektrolytische Verfahren mit einer Oxyde enthaltenden Zwischenschutzschicht auf Ventilmetallbasis und Verfahren zur Herstellung der Elektrode

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0129088B1 (de) * 1983-06-21 1987-05-20 SIGRI GmbH Kathode für wässrige Elektrolysen
DE3344416A1 (de) * 1983-12-08 1985-12-05 Sigri GmbH, 8901 Meitingen Verfahren zur herstellung einer kathode fuer die waesserige elektrolyse
US4938851A (en) * 1984-12-14 1990-07-03 De Nora Permelec S.P.A. Method for preparing an electrode and use thereof in electrochemical processes
FR2579628A1 (fr) * 1985-03-29 1986-10-03 Atochem Cathode pour electrolyse et un procede de fabrication de ladite cathode
EP0198752A1 (de) * 1985-03-29 1986-10-22 Elf Atochem S.A. Kathode für Elektrolyse und deren Herstellungsverfahren
WO1986006108A1 (en) * 1985-04-12 1986-10-23 Oronzio De Nora Impianti Elettrochimici S.P.A. Electrodes for use in electrochemical processes and method for preparing the same
US4975161A (en) * 1985-04-12 1990-12-04 De Nora Permelec S.P.A. Electrodes for use in electrochemical processes and method for preparing the same
EP0298055A1 (de) * 1987-06-29 1989-01-04 Permelec Electrode Ltd Kathode für Elektrolyse und Verfahren zur Herstellung derselben
US4900419A (en) * 1987-06-29 1990-02-13 Permelec Electrode Ltd. Cathode for electrolysis and process for producing the same
WO1992022909A1 (en) * 1991-06-13 1992-12-23 Purdue Research Foundation Solid state surface micro-plasma fusion device
WO2023037010A3 (en) * 2021-09-13 2023-05-19 Magneto Special Anodes B.V. An electrolyzer electrocatalyst comprising cobalt (co) oxide, zirconium (zr) and a noble metal, an electrode comprising the electrocatalyst and the use of the electrocatalyst in an electrolysis process

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BR8402693A (pt) 1985-05-07
FI842145A (fi) 1984-12-01
NO164487B (no) 1990-07-02
DD232514A5 (de) 1986-01-29
JPS59232284A (ja) 1984-12-27
FI842145A0 (fi) 1984-05-29
PL247951A1 (en) 1985-02-27
HUT34562A (en) 1985-03-28
AU2874984A (en) 1984-12-06
JPH0375635B2 (de) 1991-12-02
ZA844069B (en) 1986-01-29
FI75872B (fi) 1988-04-29
CS409284A2 (en) 1990-07-12
KR840009124A (ko) 1984-12-24
NO842156L (no) 1984-12-03
DD253648A1 (de) 1988-01-27
PL143728B1 (en) 1988-03-31
FI75872C (fi) 1988-08-08
ATE50003T1 (de) 1990-02-15
HU201124B (en) 1990-09-28
IN161186B (de) 1987-10-17
NO164487C (no) 1990-10-10
AU580002B2 (en) 1988-12-22
CA1246008A (en) 1988-12-06
EP0129734A3 (en) 1985-06-05
DE3481203D1 (de) 1990-03-08
KR870001769B1 (ko) 1987-10-06
CS273157B2 (en) 1991-03-12
EP0129734B1 (de) 1990-01-31

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